| Summary: | 碩士 === 國立中興大學 === 水土保持學系所 === 94 === The land-use classification of slope-land and its identification is a statutory task. The government has enforced the result of the task to limit land-use as to balance utilization with conservation of slope-land as well as to let the resources of the slope-land can be used sustainable and safe. Recently, Use digital elevation model (DEM) to analyze the terrain has become a popular technique in resource investigation. With application of geographical information system (GIS), the spatial characteristics of slope can be rapidly understood by overlaying analysis in office work. Current practice of land-use classification on slope-land and its identification is based on in-situ field examination. Therefore, application of DEM in slope-land judgment and identification is necessary to increase the accuracy of result and the operation speed.
This study used the digitized cadastral database and DEM to apply GIS software package ArcGIS with its analytical function of application modulus to handle large amount of cadastral and topographical data. Each cadastral unit is analyzed for its slope classifications. In addition, differences were evaluated among the results made from several different resolutions of DEM. The results were also compared with the actual field identification results. Discussions are made on what kind of DEM resolution is the most suitable to be analyzed in fitting field identification results.
The results of this study are as following: (1) The resulted accuracy by using DEM and GIS for classification and identification showed good consistence on land-use suitability for agricultural and forestation. (2) The key factors those influence the identification accuracy are found to be the land-use classification and complexity of the topography. (3) The 5m DEM is suitable for mild slope area and the 20m DEM is suitable for steep area. (4) The 5-th and 6-th slope class are the critical zone for agricultural and forestation, and the large difference of hand calculation with computer calculation is the key point of result consistence. (5) The results of this study can be referenced to find a more rational approach for slope-land land-use classification and identification.
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